Consider the example of an assembly operation in which a stack of parts are fastened together. The parts are clamped together with hundreds of pounds of force, while fasteners such as rivets or bolts are inserted into the stack and then terminated.
In this example, electromagnets are used to apply the clamping force. For instance, an array of electromagnets may be positioned on one side of the stack, while a metal plate is positioned on an opposite side of the stack. When the electromagnets are actuated, they create a magnetic field whose flux lines flow through the plate and move the plate towards a least reluctance position (towards the electromagnets). As a result, the parts are clamped together.
To obtain hundreds of pounds of clamping force, large electromagnets and high currents are used. High current is applied constantly during a clamping cycle. During a long clamping cycle, total energy usage is extremely high.
A cooling system may be needed to cool the electromagnets to avoid overheating during long clamping cycles. Air or another cooling fluid may be flowed through channels between copper windings of the electromagnets. Heat carried away by the fluid may be discharged by a heat exchanger or other secondary system.